An underwater steel catenary pipeline riser (SCR) lifting frame comprises a lift frame foundation and an SCR lifting frame comprising a lift frame interface adapted to be connected to the lift frame foundation; a foundation interface; a lift guide configured to accept the lift frame foundation; and a lift slidably disposed about the lift guide, the lift comprising an SCR pull head interface configured to be connected to an SCR pull head. The underwater steel catenary pipeline riser (SCR) lifting frame and systems using it allow for flex joint repair/replacement subsea which do not require large winches, deck re-enforcements, steering winches, and heavy crane lifts required by facility mounted winches above water and also reduces required heavy lifting and overall complexity of flex joint replacement.

A controller for a dynamic positioning system, the controller being configured to determine a position of a vessel relative to a target position and to control a propulsion system of the vessel based on the determined position of the vessel relative to the target position, wherein the controller is configured to monitor a property of at least part of a riser; and adjust the control of the propulsion system accordingly.

A riser extending from a floating rig includes one or more flow control devices having at least one flow connection and having at least one control connection. A riser manifold is disposed on the riser above the one or more flow control devices and has a first mechanical connector, a first flow coupling, and a first control coupling. A rig manifold can be manipulated by an arm to couple in an automated manner to the riser manifold when running the riser from the rig. The rig manifold has a second mechanical connector that mechanically connects to the first mechanical connector of the riser manifold. Additionally, the rig manifold has a second flow coupling mating with the first flow coupling of the riser manifold for conducting flow, and has a second control coupling mating with the first control coupling of the riser manifold for conducting control.

A vessel is adapted to perform subsea wellbore related operations, involving a riser string that extends between a subsea wellbore and a vessel and that is assembled from releasably interconnected riser sections that each comprise a main riser pipe and at least one auxiliary pipe. The vessel includes an auxiliary pipe filling device adapted to fill the at least one auxiliary pipe of a riser section during a lowering step of said riser running operation, the auxiliary pipe filling device including a liquid source, e.g. for water, at least one nozzle adapted to dispense water into said auxiliary pipe, a liquid flow line, connecting the liquid source with the nozzle, and a nozzle mount that is adapted to mount the nozzle in a filling position in which the nozzle is positioned to dispense liquid into the at least one auxiliary pipe of the riser section during said lowering step.

A riser assembly includes a main body which encloses a main body main passage extending from a first end to a second end which is generally parallel to a longitudinal axis, the main body being mounted in a riser so that that the main body main passage forms a part of a main passage of the riser. A first port and a second port extend through the main body to connect the main body main passage with an exterior of the main body. A tubular extends along the main body main passage. A first sealing assembly is arranged in the main body between the first port and the second port. The first sealing assembly provides a seal between the main body and the tubular. At least two diversion lines extend from the first port to the second port. A pump is arranged within each diversion line.

A pliant link to mitigate fatigue-inducing motion of a subsea catenary riser has an articulated spine having a longitudinal series of interconnected rigid segments. The spine can be coupled to upper and lower sections of the riser to transmit loads along the riser through the link on a load path that extends through the segments. The link also has a pliant pipe terminating in end fittings that can be joined, respectively, to the upper and lower sections of the riser for fluid communication along the riser through the link.

A system and a method for an offshore platform that is self-installing, not requiring use of a heavy lift vessel for installation at a site. The system has a built-in, retractable, suspended, conductor guide support frame assembly coupled to the hull of the platform and serves as lateral guide/support for the well conductors/casings during operational conditions. The conductor guide support frame assembly is generally raised during wet tow/transit. At the site, the conductor guide support frame assembly is lowered and secured into the sea to its designated elevation. The conductor guide support frame assembly generally remains suspended from the hull and does not need to extend all the way to the seabed foundation. After operations are completed, the conductor guide support frame assembly is generally raised up relative to the hull, and the whole platform with the conductor guide support frame assembly relocated for reuse at a new site.

This disclosure includes auxiliary-line riser segment assemblies (e.g., with isolation units) that are suitable for managed pressure drilling (MPD) and that can be lowered (e.g., when connected to other riser segment assemblies) through a rotary of a drilling rig. Some embodiments are configured to have portions of the auxiliary lines connected (e.g., without welding) below the rotary.

A vessel adapted to perform subsea wellbore related operations involving a riser string that is assembled from releasably interconnected riser sections and extends between a subsea wellbore and the vessel. The riser string vertical handling system of the vessel comprises a controlled motion device that is adapted to displace the riser string lifting tool in at least one horizontal direction relative to the riser spider device at least whilst travelling between said elevated and lowered position thereof loaded by the riser string suspended from the riser string lifting tool, thereby allowing to establish an inclined travel path with selectively variable inclination of the riser string lifting tool relative to an imaginary vertical line through the riser string passage of the riser spider device, e.g. said inclined travel path having an inclination selected to correspond to an actual water current induced inclination of an upper portion of the riser string during the riser string assembly process.

The invention relates to floating platform mooring and involves an improved platform mounted tendon tension monitoring system with porch-mounted variable reluctance measurement technology sensors configured. The variable reluctance measurement technology sensors of this system are optimized for porch mounting. The porch-mounted tendon tension monitoring system can also be configured such that the porch-mounted optimized variable reluctance measurement technology sensors are replaceable. Sensors may be replaced to extend the desired useful lifetime of a tendon tension monitoring system or in the event that a sensor happens to malfunction. A plurality of variable reluctance measurement technology sensors can be configured in sensor packs at the corners or at other locations where tendon tension monitoring can be useful for a floating platform.